Explain the concept of using a thread pool for task processing in a multithreaded application.

A worker pool is a mechanism that allows limiting the number of concurrently running threads (goroutines in Go) for task processing. Instead of creating a new goroutine for each task, tasks are placed in a queue, and a fixed number of workers (goroutines) process them sequentially. This helps control resource usage, avoid excessive goroutine creation, and improve performance.

In Go, a pool can be implemented using a task channel and a fixed number of worker goroutines that read tasks from the channel and execute them:

func worker(id int, jobs <-chan int, results chan<- int) {
    for j := range jobs {
        // process task j
        results <- j * 2
    }
}

func main() {
    jobs := make(chan int, 100)
    results := make(chan int, 100)

    // Launch 3 workers
    for w := 1; w <= 3; w++ {
        go worker(w, jobs, results)
    }

    // Send 5 tasks
    for j := 1; j <= 5; j++ {
        jobs <- j
    }
    close(jobs)

    // Collect results
    for a := 1; a <= 5; a++ {
        fmt.Println(<-results)
    }
}

This approach allows efficient management of concurrency and application resources.